What Causes Muscle Contractions to Be Graded

question 20

Multiple Choice

What causes muscle contractions to be graded?

• A) increasing stimulus frequency
• B) both increasing stimulus strength and increasing stimulus frequency
• C) increasing stimulus strength

---

Definitions:

Melanocytes

Cells located in the lower layer of the skin's epidermis and in the hair follicles, responsible for producing the pigment melanin, which colors the skin, hair, and eyes.

Vitiligo

A condition in which the skin loses its pigment cells, resulting in discolored patches.

Papillary Layer

The upper layer of the dermis that contains blood capillaries, sensory neurons, and the bases of the hair follicles.

Dermis

The dermis is the thick layer of living tissue below the epidermis that forms the true skin, containing blood capillaries, nerve endings, sweat glands, hair follicles, and other structures.